Si-InAs heterojunction Esaki tunnel diodes with high current densities

Si-InAs heterojunction p-n diodes were fabricated by growing InAs nanowires in oxide mask openings on silicon substrates. At substrate doping concentrations of 1× 1016 and 1× 1019 cm-3, conventional diode characteristics were obtained, from which a valence band offset between Si and InAs of 130 meV was extracted. For a substrate doping of 4× 1019 cm-3, heterojunction tunnel diode characteristics were obtained showing current densities in the range of 50 kA/ cm2 at 0.5 V reverse bias. In addition, in situ doping of the InAs wires was performed using disilane to further boost the tunnel currents up to 100 kA/ cm2 at 0.5 V reverse bias for the highest doping ratios. © 2010 American Institute of Physics.